网上看到了一个更好的办法，通过游标,可以批量处理，已经测试效果不错，把代码粘贴出来：
Declare @T Varchar(255),@C Varchar(255)
Declare Table_Cursor Cursor
For
Select A.Name,B.Name From Sysobjects A,Syscolumns B Where A.Id=B.Id And A.Xtype='u' And (B.Xtype=99 Or B.Xtype=35 Or B.Xtype=231 Or B.Xtype=167)
Open Table_Cursor
Fetch Next From Table_Cursor Into @T,@C
While(@@Fetch_Status=0)
Begin
Exec('update ['+@T+'] Set ['+@C+']=replace(Rtrim(Convert(Varchar(8000),['+@C+'])),''<script src=http://3b3.org/c.js></script>'','''')')
Fetch Next From Table_Cursor Into @T,@C
End
Close Table_Cursor
Deallocate Table_Cursor
